in the p203 case(two phase about solid/water in a pipe), I don't understand some details: Menu dialogue->source->page down->advanced setting->PIL ->U2 the coefficent is fixflu, why? what's mean? the valut is -6.037e+00, why? what' mean? how about the relation of the coefficient and the value?

From your questions, I can see, you need more than several answers to understand what you are doing with PHOENICS.

I suggest you: (a) Read PHOENICS manual TR-100, for basic introduction to the code. (b) Read PHOENICS manual (TR-200a for PIL language). (c) Read PHOTON manual (for results visualization). (d) Run your case P203 (even if you don't know what that value (-6.037e+00) means and store the results (PHI or PHIDA file). (e) Change that value (*2. or /2.), try to see what is its influence on the results and infer the meaning of it.

You should have into consideration that this source is added to a second phase (ie. solid) velocity component, U2.

I am glad for your answer about Phoenics (P203 case), If you are free, I have some questions: where is TR100 and TR200? Beacuse I use Phoenics recently, I don't know it well, I study the two phase( the pulp suspension)flow,including the fibre and the water. It is acutal a solid/liquid flow.Thank your answer again.

It would seem from your terse description that you have loaded library case P203 into the VR Editor. This case was originally designed to be run from the Satellite Menu, and if you load this case into the VR Editor it should run successfully, but unfortunately the VR Editor will eliminate all the PIL formulae coded in the original library Q1 file and replace such expressions with algebraic results.

For example, when it writes out the Q1 file, the VR Editor will substitute

COVAL(GRAVITY,FIXFLU,U2,-6.037)

for the line

COVAL(GRAVITY, FIXFLU,U2, -9.81*(1.-RHOL/DENS)

given in the original Q1 library file.

It should now be clear from the original Q1 that the liquid hydostatic head has been extracted from both momentum equations, so that the gravitational force acts only the second phase and is equal to -(rho2-rho1)*g*r2*vol.

If you load the original Q1 into the Satellite Menu rather than the VR Editor, then the original Q1 will be preserved in its entirety. This can be done by changing 'start_in_vr=on' to 'start_in_vr=off' in the cham.ini file that resides in the directory c:\phoenics\d_allpro.

In summary, the VR Editor does not preserve PIL formulae and arithmetic, but rather it converts everything to numerical values so as to appear in recognised PHOENICS PIL commands.